JP2002204543A - Rotating electric machine for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotating electric machine for a vehicle which can prevent electrolyte and foreign matters to be left untransported for the joint of a stator winding. SOLUTION: The stator winding of an AC generator for a vehicle is formed by inserting a conductor segment 33, which is formed into an almost U shape each slot of the stator winding and then joining end portions 33e of the conductor segments 33 inserted into different slots. Since a bare portion 33h, where a film does not exist on the surface, is formed at the region near the end portions 33e of the conductor segment 33, the film does not undergo thermal deterioration, when the junction is subjected to soldering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular rotating electric machine mounted on a passenger car, a truck or the like.

[0002]

2. Description of the Related Art In recent years, in response to demands such as a reduction in idling speed of a vehicle as a measure against environmental problems, a reduction in weight for improving fuel efficiency, and a reduction in an engine room for securing a cabin space, an engine has been developed. 2. Description of the Related Art In-vehicle rotating electric machines such as driven AC generators are required to be reduced in size and output. To meet these demands, Japanese Unexamined Patent Application Publication No.
BACKGROUND ART A vehicle alternator disclosed in 000-69729 is known. In this automotive alternator, a stator winding is formed by a plurality of conductor segments, and the conductor segments of different layers protruding from different slots are connected to each other, so that the stator winding has a higher linear product ratio and a lower stator winding. Realizes resistance.

On the other hand, in an engine room in which an alternator for a vehicle is mounted, a large amount of electrolyte such as car shampoo and salt water and foreign substances such as dust and dust during traveling come in, so that the performance can be improved even in such an environment. Need to be maintained. In particular, since the vehicle alternator cools each part by the cooling air generated by the fan, there is a great possibility that the electrolyte and foreign matter reach the inside of the vehicle alternator together with the cooling air,
Ensuring the environmental integrity of the stator is an important issue.

[0004]

By the way, in the vehicle alternator disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2000-69729, the stator winding is formed by welding the ends of a plurality of conductor segments by welding. Therefore, the temperature of the joint and the vicinity thereof becomes high. For example, when a coating does not exist at the joint and there is a coating in the vicinity, the coating near the joint deteriorates due to thermal stress applied at the time of joining. As a problem due to the deterioration of the coating, there has been a problem that a portion where the coating has deteriorated is apt to be peeled or cracked, and an electrolyte or a foreign substance stays in a void generated by the peeling or cracked. Also, if there is a coating on the joint, the coating will be rolled up and joined, and the bonding condition will not be stable. There is a problem that foreign matter stays. It is also conceivable to coat the joint with a resin material in order to improve the insulating property.However, if there is peeling or cracking of the coating deteriorated by thermal stress at that time,
Since the resin material is less likely to adhere, environmental performance is reduced. Furthermore, when considering joining by welding, the molten conductor protrudes from the end face of the original conductor segment in both the circumferential direction and the radial direction at the joint and solidifies,
The distance between the joints adjacent in the circumferential direction is shortened, and the short circuit is easily caused.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicular rotating electric machine capable of preventing an electrolyte or foreign matter from staying at a joint of a stator winding. To provide.

[0006]

In order to solve the above-described problems, a rotating electric machine for a vehicle according to the present invention comprises a rotor, a stator core, and a plurality of coated conductor segments provided on the stator core. And a frame that supports the rotor and the stator. The plurality of conductor segments have a joining portion in which the ends are joined in a circular shape by arranging the ends in the radial direction and the circumferential direction, and the ends are joined by welding. Has a bare portion which is a non-coating region. The joint and its vicinity become hot at the time of joining by welding, but since there is no film formed in this part, there is no thermally deteriorated film,
It is possible to prevent foreign matter such as an electrolyte from entering and staying in the thermally deteriorated portion of the coating. In addition, when there are many joints made of insulating resin, there is no deteriorated film, so this insulating resin easily adheres to the conductor and the film, and can be sufficiently coated with a small amount and improve environmental performance. Can be done. In other words, environmental properties are improved when there is no degraded film due to peeling or cracking. In other words, it is better that the coating is not present before the bonding in the joint and the portion where the coating in the vicinity thereof is deteriorated, and the environment is improved by providing a bare portion in such a portion to prevent the deterioration of the coating. be able to.

[0007] It is desirable to form a gap between adjacent joints which are arranged in an annular shape. Thus, the cooling performance can be improved by reducing the ventilation resistance of the cooling air, and the effect of discharging foreign matter that has entered the inside of the frame can be enhanced.

It is desirable that the above-mentioned joint is covered with an insulating resin to form a plurality of irregularities along the circumferential direction. Since the deteriorated coating does not exist on the surface of the conductor segment, the insulating resin easily adheres when the joint is covered with the insulating resin, and the joint can be sufficiently covered with a small amount of resin. Thereby, it is possible to prevent a short circuit between the junctions and to improve the environmental performance. In addition, by forming the concavo-convex shape, it is possible to improve the cooling performance by increasing the surface area.

The above-mentioned conductor segments are arranged in two or more rows in the radial direction in slots provided in the stator core, and the length of the joint portion in the radial direction is determined by the length of the conductor segment to be joined. It is desirable that the length be shorter than the total length along the radial direction. This makes it possible to secure a distance between the radially adjacent joints and a distance between the outermost joint and the inner frame wall outside the joint, thereby preventing a short circuit therebetween.

[0010] Further, it is desirable that the bare portions provided on the two joined conductor segments have flat surfaces adjacent to each other. Thereby, the stability of joining can be improved.

[0011] It is desirable that the bare portion provided on the two joined conductor segments has a flat surface opposite to the adjacent surface. Thereby, a gap between the joints along the radial direction can be secured, and a short circuit between the joints can be prevented.

[0012] Further, it is desirable that the side surfaces of the adjacent surfaces of the bare portions provided on the two joined conductor segments are flat. As a result, it is possible to secure a gap between the circumferentially adjacent joints, thereby improving the cooling performance by reducing the ventilation resistance of the cooling air, and at the same time, discharging foreign substances entering the frame. Can be increased.

It is desirable that the cross section of the above-mentioned bare portion has a substantially polygonal shape. Since the surface adjacent to the bare portion can be reduced, the insulating resin easily adheres to the other surface, and the environmental performance can be improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle AC generator according to an embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing the overall structure of an automotive alternator according to one embodiment. As shown in the figure, the vehicle alternator 1 of the present embodiment includes a rotor 2, a stator 3,
It is configured to include a frame 4, a rectifier 5, and the like.

The rotor 2 includes a field coil 8 formed by winding an insulated copper wire cylindrically and concentrically, and each of the field coils 8 comprises a coil 6.
It has a configuration in which it is sandwiched from both sides through a shaft 6 by a pole core 7 having a plurality of claw portions. An axial-flow-type cooling fan 11 is attached to the end face of the pole core 7 on the front side by welding or the like to discharge the cooling air sucked from the front side in the axial direction and the radial direction. Similarly, a centrifugal cooling fan 12 is attached to the end face of the rear pole core 7 by welding or the like to discharge the cooling air sucked from the rear side in the radial direction.

The stator 3 includes a stator core 32, a plurality of conductor segments 33 constituting the stator winding 31, and an insulator 34 for electrically insulating the stator core 32 and the conductor segments 33. I have. The stator core 32
It is formed by laminating thin steel plates, and has a large number of groove-like slots formed on its inner peripheral surface. A sheet-like insulator 34 is arranged along the inner wall surface of the groove-like slot. In the slot, the conductor segment 33 is electrically insulated from the stator core 32 by an insulating coating formed on its surface and an insulator 34. In addition, this stator core 32
The coil end 35 of the stator winding 31 is formed by the conductor segment 33 exposed from the coil. Stator 3
The detailed structure of will be described later.

The frame 4 houses the rotor 2 and the stator 3, and the rotor 2 is supported so as to be rotatable about a shaft 6, and is provided on the outer peripheral side of the pole core 7 of the rotor 2. Stator 3 arranged via a predetermined gap
Has been fixed. The frame 4 is provided with a cooling air discharge hole 42 at a portion facing the coil end 35 of the stator 3.
However, suction holes 41 are provided on the axial end surfaces, respectively.

AC generator 1 for vehicle having the above-mentioned structure
When a rotational force from an engine (not shown) is transmitted to the pulley 20 via a belt or the like, the rotor 2 rotates in a predetermined direction. In this state, by applying an excitation voltage to the field coil 8 of the rotor 2 from the outside, each claw portion of the pole core 7 is excited, and a three-phase AC voltage can be generated in the stator winding 31. A predetermined direct current is extracted from the output terminal of the rectifier 5.

Next, the details of the stator 3 will be described.
The stator winding 31 of the present embodiment is configured by arranging a plurality of U-shaped conductor segments 33 according to a predetermined rule and electrically connecting the ends thereof.

FIG. 2 is a perspective view schematically showing a conductor segment 33 constituting a stator winding. The stator winding 31 is formed by using the two conductor segments 33a and 33b as a basic unit and arranging a plurality of these units.

The U-shaped conductor segment 33 has a turn 33c and an end 33e. Turn part 33c
Forms a coil end 35 on the rear side (opposite to the pulley side) together with the skewing portion 33d following this. The end 33e is connected to the drive side (pulley side) together with the following skewing section 33f.
Is formed.

The ends 33e of the conductor segments 33 are joined to each other by, for example, TIG (tungsten insert).
-Gas) preferably by welding. FIG.
FIG. 4 is a perspective view showing an end before joining conductor segments. FIG. 4 is a perspective view showing an end portion after the conductor segments are joined.

As shown in FIG. 3, the end portions 33e of the adjacent conductor segments 33 are arranged adjacent to each other in contact with each other, and the tungsten electrodes are brought close to each other to generate an arc between the end portions 33e and the base material so that the local portions are locally formed. And solidified again. As a result, as shown in FIG. 4, a joining portion 33g having a droplet-like portion as a melting mark is formed. At this time, since the joining portion 33g is melted into a droplet by welding, the length L2 along the radial direction of the joining portion 33g after joining is smaller than the length L1 along the radial direction of the end portion 33e before joining. Is shorter.

FIG. 5 is a plan view of the stator 3 as viewed from the joint 33g side. As shown in FIG. 5, the joining portions 33g of the two conductor segments 33 are annularly arranged in one row. Further, since the stator winding 31 of the present embodiment has two conductor segments 33a and 33b as a basic unit as shown in FIG. 2, the joining portions 33 are provided at two locations in the radial direction.
g, and these joints 33g are arranged in two rows concentrically and annularly as a whole.

FIG. 6 is a diagram showing the state of the film near the joint 33g. FIG. 7 is a view showing a state of a film near a conventional joint. The conductor segment 33 of the present embodiment has a bare portion 33h on which no coating is formed so as to be adjacent to the joining portion 33g. By providing the bare portion 33h, it is possible to prevent peeling or cracking of the thermally deteriorated coating when forming the joint 33g by TIG welding. On the other hand, as shown in FIG.
When the coating in only the minimum area necessary for joining is removed, the coating 33k in the area 33i adjacent to the joint 33g is deteriorated by the heat transmitted during welding, and peeling or cracking occurs. In addition, how much the naked part 33h should be secured is
It may be set by actually performing TIG welding using a conductor segment in which the coating is formed up to the vicinity of the joint 33g as shown in FIG. 7 and examining the range of the region 33i where the coating has deteriorated.

In the embodiment shown in FIG. 8, a bare portion is provided at a predetermined interval from an adjacent segment to a range that does not reach a portion that first intersects, and is covered with a resin. But,
When the amount of heat input at the time of joining is increased in order to further increase the strength of the joint, the heat-degraded portion of the coating often reaches the portion 33p where the adjacent segment first intersects with a predetermined interval. Therefore, even if the heat-degraded portion of the coating film is covered with the resin, the adhesion of the resin to the heat-deteriorated portion is poor, and it is conceivable that insulation from adjacent segments becomes insufficient due to the invasion of water or the like from the outside. In this case, as shown in FIG. 11, the bare portion is set to a portion 33p that first intersects with an adjacent segment from the tip of the joining portion with a predetermined interval, and the durability can be secured by covering the portion with a resin. . That is, it is possible to secure the durability by covering the area up to the vicinity of the second intersecting portion 33q from the joint with the resin.

In the embodiment shown in FIG. 11, the bare portion is provided from the leading end of the joining portion to the portion where the adjacent segment first intersects with a predetermined interval. However, depending on the heat input conditions, the bare area and the area covered by the resin are the second and third from the joint.
It may be set to be even wider, such as to the portion where it intersects.

Further, as shown in FIGS. 3 and 4, the above-described bare portion 33h is formed on an adjacent surface (see FIG.
It is preferable that the surfaces 33M shown in FIG. 3 and the surfaces (the surfaces 33L and 33N shown in FIGS. 3 and 4) facing the joining portion 33g adjacent in the radial direction and the circumferential direction are flat surfaces. By making the surface 33M a flat surface, it is possible to enhance the stability of bonding. Further, by making the surface 33L a flat surface, the joining portion 33g and the bare portion 33
h, or between the outermost joint 33g or the bare part 33h and the inner wall of the frame 4. Further, by making the surface 33N a flat surface, a gap can be secured between the joining portion 33g and the bare portion 33h that are adjacent in the circumferential direction. By securing the gap in this way, it is possible to prevent short circuit, improve cooling performance, and improve environmental performance.

FIG. 8 is a diagram showing the stator winding 31 in which the joint 33g is covered with an insulating resin. As shown in FIG. 8, in the present embodiment, after forming the bonding portion 33 g, the insulating resin 3
6 covers the entire joint 33g. In addition, a gap is formed between the joining portions 33g that are adjacent to each other along the circumferential direction, and the distal end portion has a substantially uneven shape.

As described above, the stator winding 31 of this embodiment is
Since each conductor segment 33 is provided with a bare portion 33h, the conductor segment 33 adjacent to the joining portion 33g is provided.
There is no thermal deterioration of the coating on the surface of. For this reason, it is possible to prevent foreign matters such as an electrolytic solution from entering and staying in the thermally deteriorated portion of the coating. Further, even when the joint 33g is covered with the insulating resin 36, the adhesion of the insulating resin 36 is good, and the joint 33g can be sufficiently covered with a small amount, thereby reducing the material cost and improving the environmental performance. Can be achieved.

Also, by reducing the amount of the insulating resin 36 used, the gap between the adjacent joints 33g can be widened, so that the ventilation resistance of the cooling air can be reduced, and the cooling performance can be improved. The effect of discharging foreign matter that has entered the inside of the frame 4 can be enhanced, and the environmental performance can be further improved.

Further, by setting the radial length of the joining portion 33g shorter than the radial length of the end portion 33e before joining, between the joining portions 33g adjacent in the radial direction,
The effect of preventing a short circuit between the outermost joint 33g and the inner wall of the radially outer frame 4 can also be enhanced.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, the U-shaped conductor segment 33 is used. However, as shown in FIG. 9, a conductor segment 331 having no turn may be used to join both ends 331e. .

Also, in the above-described embodiment, the number of the conductor segments 33 in the slot is set to 4 to form two rows of annular joints. However, the number of the conductor segments is changed according to the required output characteristics. Alternatively, the number of annular rows of the joints may be changed.

In the above-described embodiment, as shown in FIG. 3, the length of the end 33e of the conductor segment 33 along the radial direction is the same as that of the other portions of the conductor segment 33. As shown in FIG. 10, a notch or the like may be provided on the side opposite to the contact surface between the ends 33e ′, so that the radial length of the joint may be further reduced.
In this case, a larger gap can be secured between the joints adjacent in the radial direction or between the outermost joint and the inner wall surface of the frame 4, thereby preventing a short circuit. Cooling performance and environmental performance can be improved.

In the above-described embodiment, the bare portion 33h
Although the cross-sectional shape is formed in a quadrangle, it may be formed in a polygonal shape that is a quadrangle or more. Since the contact surface between the bare portions can be further reduced, the insulating resin can easily enter the gap formed between the adjacent bare portions, and the environmental performance can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an overall structure of a vehicle alternator according to an embodiment.

FIG. 2 is a perspective view schematically showing conductor segments constituting a stator winding.

FIG. 3 is a perspective view showing an end before joining conductor segments.

FIG. 4 is a perspective view showing an end portion after joining conductor segments.

FIG. 5 is a plan view of the stator viewed from the joint side.

FIG. 6 is a diagram showing a state of a film near a joint.

FIG. 7 is a view showing a state of a film near a conventional joint.

FIG. 8 is a diagram showing a stator winding in which a joint is covered with an insulating resin.

FIG. 9 is a perspective view showing a conductor segment without a turn portion.

FIG. 10 is a perspective view showing another example of the end of the conductor segment.

FIG. 11 is a diagram showing another example of a stator winding in which a joint is covered with an insulating resin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Rotor 3 Stator 4 Frame 31 Stator winding 32 Stator iron core 33 Conductor segment 33e End 33g Joint 33h Bare part 34 Insulator

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H603 AA09 BB02 BB07 BB09 BB12 CA01 CA05 CB03 CB17 CC03 CC13 CC17 CD02 CD05 CD06 CD08 CD11 CD12 CD22 CE02 CE05 CE12 EE01 FA01 FA16 5H604 AA05 AA08 BB03 BB10 CC01 CC01 CC13 PC03

Claims (8)

[Claims] 1. A vehicle having a rotor, a stator having a stator core and a plurality of coated conductor segments provided on the stator core, and a frame supporting the rotor and the stator. In the rotating electrical machine, the plurality of conductor segments have a joining portion in which ends are joined by welding and end portions are arranged in a radial direction and a circumferential direction and arranged in an annular shape. A rotating electric machine for a vehicle, characterized by having a bare portion which is a region where the film is not formed on a part of the rotating electric machine. 2. The vehicular rotating electrical machine according to claim 1, wherein a gap is formed between the joining portions that are arranged in an annular shape and are adjacent to each other. 3. The rotating electric machine for a vehicle according to claim 1, wherein the joining portion is covered with an insulating resin to form a plurality of irregularities along a circumferential direction. 4. The joint according to claim 1, wherein the conductor segments are arranged in two or more rows along a radial direction in slots provided in the stator core, and Is smaller than the total length of the conductor segments to be joined along the radial direction. 5. The rotating electric machine for a vehicle according to claim 1, wherein adjacent surfaces of the bare portions provided on the two joined conductor segments are flat. 6. The vehicle rotation according to claim 1, wherein the bare portion provided on the two joined conductor segments has a flat surface opposite to an adjacent surface. Electric machine. 7. The rotating electric machine for a vehicle according to claim 1, wherein adjacent sides of the bare portion provided on the two joined conductor segments are flat. . 8. The rotating electric machine for a vehicle according to claim 1, wherein a cross section of the bare portion has a substantially polygonal shape.